Aloha protocol in data communication and networking
- 1. LOHA LOHA
- 2. WHAT IS MAC ?• When nodes are connected with a shared line ,called multipoint. •We need many protocol to handle shared link. •All of these protocol belong to a sub layer in a data link layer called media access control (MAC).
- 5. No station is superior to another station. Transmission is random among station. That’s why this method is known as random access method. Random access protocol
- 7. WHAT IS ALOHA ? •Aloha means "Hello". • ALOHA is a system for coordinating to a shared communication networks channel. •It is random access method.
- 9. PURE ALOHA •It is original ALOHA. •It sends frame whenever it has frames. •There is possibility of collision in it. •If acknowledgement is not received within specified time,it resends data.
- 10. Pure ALOHA
- 11. Slotted ALOHA •Slotted ALOHA was invented to improve the efficiency of pure ALOHA developed by Roberts in 1972. • In slotted ALOHA, the time of the shared channel is divided into discrete intervals called slots. •In slotted ALOHA, there is still a
- 12. Slotted ALOHA
- 13. PURE ALOHA VS SLOTTED ALOHA Pure ALOHA It is less efficient. Pure Aloha is a Continuous time system. Pure ALOHA doesn't check whether the channel is busy. More efficient. slotted Aloha is a non continuous time system. slotted ALOHA checks whether the channel is busy. Slotted ALOHA
- 14. Reference •Data communication and networking, By Forouzon • www.slideshare.com •www.computernotes.com